The present invention is directed to the disposal of waste and more particularly to a transportable manifold apparatus for generating a curtain of high-velocity air over and into a waste combustion trench or chamber.
The disposal of waste such as trees, brush, yard waste, etc. is a major concern of the municipal, commercial and private sectors. Various types of recycling equipment and techniques are in use or have been proposed to dispose of such waste, all with varying degrees of success.
One method is to transport the waste to a landfill and bury the waste. However, landfill sites are becoming scarce and those remaining are cost prohibitive especially in rapidly growing urban areas. In addition, even if suitable sites can be found, they are often at a distance that makes transportation costs prohibitive. Since vegetation waste makes up approximately 40% of the bulk typically buried in landfills, most large cities require that the waste be separated from conventional garbage for purposes of mulch and compost manufacture in an effort to recycle the waste.
Each year there are tens of thousands of acres of land cleared of trees, brush, etc. for development and millions of tons of yard waste (small branches, leaves, grass, etc.) produced. Reducing the amount of such waste being buried or mulched would significantly reduce the pressure on the existing landfills and delay the need for opening new landfill sites. In addition, landfills are a relatively inefficient method of recycling. Being simply buried at one site, the economic potential of the waste material is never fulfilled. Also, solid waste landfills are diminishing rapidly and permits for new sites are difficult to secure.
Another waste material that presents challenges with regard to disposal is animal carcasses. In the past, diseased animal carcasses were usually buried and forgotten. Little was known about the agents that caused the deadly diseases which have wiped out many herds of cattle and entire chicken farms. It has been discovered that certain pathogens can survive for over fifty years in the soil where they have been buried along with animal carcasses that perished from the disease.
One alternative to landfills has been to incinerate the waste material. With regard to wood and vegetation wastes, this produces an ash residue which is extremely high in natural nutrients beneficial for plant growth. When the ash is mixed with compost and varying amounts of soil, a range of products from high-grade potting soil to top soil are developed. Open burning of the vegetation waste on site is the simplest and most cost effective way of incinerating the waste material. However, due to the many environmental limitations imposed by federal, state, and local jurisdictions, open burning is not always feasible or possible. With regard to the disposal of animal carcasses, the only known practical approach to the elimination of diseased carcasses is high temperature incineration.
Some open pit incineration has been made possible through the use of air curtain incinerators such as the device disclosed in U.S. Pat. No. 4,756,258. In an open pit incinerator, the waste is loaded into a fire pit or trench through an opening and then ignited. High velocity air from a manifold positioned along the opening is then blown over and into the trench. The air flow pattern is intended to over-oxygenate the fire for more complete combustion and to provide a rotating mass of air that acts as a barrier or curtain to reduce the emission of smoke and ash from the fire. At many landfill sites, incineration trenches are dug at various locations on the site to reduce the amount of waste to be buried. It is also commonplace to dig and use incineration trenches at land clearing sites to reduce waste and generate soil nutrients, at forest service operation sites to reduce fuel for forest fires and clean post-fire debris, at wood products manufacturing sites to reduce waste, and at disaster sites to facilitate clean-up from a storm or flood or dispose of diseased animal carcasses.
Because road and highway transport of waste materials is costly, and in the case of diseased animals is undesirable for many reasons, the capability to provide an on-site incineration trench and means for generating an air curtain at the trench is beneficial. The aforementioned device of U.S. Pat. No. 4,756,258 provides a transportable trench burner comprising a trailer subassembly 10 carrying a blower source and a manifold subassembly 20 which can be assembled in the form of a T-shaped conduit extending from the blower source. The manifold subassembly is in individual pieces that must be fully disassembled from each other and stored on the trailer subassembly for transport. U.S. Pat. No. 4,739,712 discloses a generally similar trailer-mounted trench burner wherein an air curtain nozzle 1 must be disconnected from an air supply conduit 2 and stored atop the air supply conduit for transport. These trailer-mounted trench burners of the prior art are time consuming to assemble and disassemble, and require considerable trailer space to carry the disassembled parts. Moreover, hardware for securing the assembly connections is susceptible to being lost and must then be replaced.
U.S. Pat. No. 5,415,113, which is assigned to the assignee of the present invention, discloses a portable incineration apparatus that provides an air curtain for reducing the emission of smoke and ash and to provide for more complete combustion of the waste materials. The apparatus provides a box having four walls with a top opening and a bottom opening. The inside of the walls are lined with a layer of a refractory material to form a combustion chamber. The incinerator also includes a source of high velocity air that is in air transfer communication with a manifold assembly to direct an effective sheet or curtain of high velocity air across the top of the opening and down into the combustion chamber. The panels that make up the side walls of the apparatus weigh up to 1200 pounds each and are constructed of refractory materials rated to withstand temperatures to 2800xc2x0 F. Thus, U.S. Pat. No. 5,415,113 provides an xe2x80x9call in onexe2x80x9d solution that avoids the need for digging a trench. Although useful, this approach adds to the cost and overall size of the apparatus.
Therefore, it is an object of the present invention to provide a relatively compact trailer-mounted trench burner that may be set up for use or compacted for transport and storage very quickly.
It is another object of the present invention to provide a trailer-mounted trench burner that requires minimal tools and hardware to set up or take down.
It is another object of the present invention to provide improved methods of setting up and taking down a trench burner.
In furtherance of these and other objects, a trailer-mounted trench burner apparatus formed in accordance with a preferred embodiment of the present invention generally comprises a trailer; a blower source supported by the trailer for providing high-velocity airflow; and a foldable airflow delivery system extendable from and retractable to the trailer on rollers. The airflow delivery system includes an elongated carrier pipe extending in a lengthwise direction of the trailer and being mounted on the trailer by roller assemblies for movement between a forward retracted position and a rearward extended position, and left and right manifolds pivotally mounted to the carrier pipe for folding movement between a storage position wherein each manifold extends alongside the carrier pipe and a usage position wherein each manifold extends in a lateral direction from the carrier pipe. The carrier pipe includes an entrance port that aligns with the blower source when the carrier pipe is extended, thereby placing the carrier pipe in flow communication with the blower source. Each manifold includes a flow deflector arranged to receive airflow from the carrier pipe when the particular manifold is unfolded out to its usage position and redirect the airflow laterally for discharge through output nozzles spaced along an air curtain axis defined by the manifolds.
The invention also encompasses novel methods for setting up an incineration trench and a trench burner apparatus and for removing a trench burner apparatus from an operating location at an incineration trench. The set up method generally comprises the steps of towing the present trench burner apparatus near to a desired trench location, arranging the airflow delivery system of the apparatus in flow communication with the blower source, unfolding the airflow delivery system to define an air curtain axis, and digging the incineration trench in edgewise adjacency to the air curtain axis. The removal method generally comprises the steps of folding the airflow delivery system, moving the airflow delivery system out of flow communication with the blower source into a retracted position on the trailer, and towing the trench burner apparatus away from the incineration trench.